A motor vehicle transmission comprises a plurality of shifting elements and a number of gearsets, such that in each engaged gear of the transmission a first number of shifting elements are closed or engaged and a second number of shifting elements are open or disengaged. Depending on the shifting positions of the shifting elements and hence depending on the gear engaged, the gearsets of the transmission produce a defined gear ratio. The shifting elements of such a transmission can be in the form of frictional shifting elements such as clutches and/or brakes, or in the form of interlocking shifting elements such as claws. Furthermore, a transmission of a motor vehicle comprises a shifting oil system and a cooling and lubricating oil system. By means of the shifting oil system, the shifting elements can be acted upon with shifting oil, to close them. By means of the cooling and lubricating oil system the assemblies of the transmission, for example its gearsets and bearings, can be acted upon by cooling and lubricating oil.
In known transmissions the cooling and lubricating oil system of the transmission serves to supply all the assemblies of the transmission with cooling and lubricating oil, in particular the gearsets, bearings and shifting elements. On the other hand the transmission's shifting oil system serves exclusively to supply the shifting elements with shifting oil. In such transmissions the shifting elements, even when they are closed or open and therefore when they are not undergoing a shifting process, are still permanently or continually supplied by the cooling and lubricating oil system with cooling and lubricating oil, i.e. even at times when relatively little heat energy is being generated at those shifting elements. This continual cooling and lubrication of the shifting elements even when they are in a closed or open condition results in relatively substantial splash losses in the transmission. Moreover, an oil pump that provides the volume flow of the cooling and lubricating oil in the cooling and lubricating oil system has to be relatively large.
Transmissions with functionally separate oil systems, i.e. a shifting oil system which serves exclusively to supply the shifting elements with shifting oil and a cooling and lubricating oil system which serves to supply the gearsets, bearings and shifting elements with cooling and lubricating oil, are known from DE 10 2004 027 113A1 and also from DE 10 2011 081 006 A1.